Growing epidemiologic research demonstrates that gay men are a vulnerable group, at higher risk for HIV, substance use, and depression, relative to their heterosexual counterparts. Experts in the field have noted that this "syndemic" of interrelated risks is likely the result of structural and cultural challenges posed by growing up and living as a member of a marginalized group. Thus, the sociological trend of increasing parenthood among a population at high risk for a variety of negative health outcomes raises multiple questions for public health, perhaps the most important of which is, What impact will parenthood have on the existing vulnerabilities within this community? Having children marks an important developmental transition for any individual, regardless of his or her sexual orientation. This transition radically reshapes an individual's life across multiple levels: changes occur to the individuals themselves, to the couple and their relationship dynamics (when parenthood occurs in a couple), and to the larger social network in which the parent exists. These changes have the potential to profoundly affect any parent's health, both for better and for worse. And when these changes occur in the life of a gay man, the stakes are higher still, as their pre-existing risks for HIV, substance use, and psychological distress interact with these life changes in ways that are poorly understood. Thus, parenthood has great potential to be both a source of protection and of danger for gay men. For example, research indicates that the transition to parenthood marks a low point for most couples in relationship satisfaction and frequency of sexual contact. While strict societal norms regarding fidelity protect many heterosexual couples during this challenging period, the relative acceptability of nonmonogamy among gay men might facilitate additional sexual contact outside the relationship, and the relatively higher incidence of HIV and STDs means that those contacts each carry greater risk for disease. However, parenthood might also mitigate other risks. For example, research has shown that the demands of caring for a child force a natural form of lifestyle regulation, which provide for fewer opportunities for parents to drink heavily or use substances. In a community with documented higher prevalence of substance use and abuse, this lifestyle regulation may be especially protective. Understanding the nuances of how parenthood intersects with gay men's unique vulnerabilities will be essential to developing interventions and public health practice to support this growing population of families. No study that we are aware of has examined how parenthood might function as a protective and/or risk factor for gay men's health and well-being. PUBLIC HEALTH RELEVANCE: The proposed study will have significant health impact for gay fathers. Specifically, we will identify psychological and behavioral factors that help prevent fathers from HIV risk, substance abuse and psychological distress as they navigate the myriad life-changing situations faced as parents. Additionally, factors associated with gay father's increased vulnerability to HIV risk, substance abuse and psychological distress will also be identified.